Association of volumetric bone mineral density with abdominal aortic calcification in African ancestry men

New Emerging Biomarkers for Bone Disease: Sclerostin and Dickkopf-1 (DKK1)

A healthy skeleton depends on a continuous renewal and maintenance of the bone tissue. The process of bone remodeling is highly controlled and consists of a fine-tuned balance between bone formation and bone resorption. Biochemical markers of bone turnover are already in use for monitoring diseases and treatment involving the skeletal system, but novel biomarkers reflecting specific biological processes in bone and interacting tissues may prove useful for diagnostic, prognostic, and monitoring purposes. The Wnt-signaling pathway is one of the most important pathways controlling bone metabolism and consequently the action of inhibitors of the pathway such as sclerostin and Dickkopf-related protein 1 (DKK1) have crucial roles in controlling bone formation and resorption. Thus, they might be potential markers for clinical use as they reflect a number of physiological and pathophysiological events in bone and in the cross-talk with other tissues in the human body. This review focuses on the clinical utility of measurements of circulating sclerostin and DKK1 levels based on preanalytical and analytical considerations and on evidence obtained from published clinical studies. While accumulating evidence points to clear associations with a number of disease states for the two markers, and thus, the potential for especially sclerostin as a biochemical marker that may be used clinically, the lack of standardization or harmonization of the assays still hampers the clinical utility of the markers.

High Cardiovascular Risk in Older Men with Poor Bone Microarchitecture-The Prospective STRAMBO Study

Data on the association between bone microarchitecture and cardiovascular disease (CVD) in men are scarce. We studied the link of bone microarchitecture and areal bone mineral density (aBMD) with the risk of major adverse coronary event (MACE) in a cohort of men aged 60 to 87 years followed prospectively for 8 years. At baseline, aBMD was measured using a Hologic Discovery-A device. Bone microarchitecture was assessed at distal radius and tibia by high-resolution peripheral quantitative computed tomography (XtremeCT Scanco device). During the study, 53 men had incident MACE. The analyses were adjusted for confounders related to bone and CVD. In 813 men (53 MACEs), higher aBMD at the lumbar spine, hip, whole body, and radius was associated with lower risk of MACE (hazard ratio [HR] = 0.44-0.71/SD, p < .025 to < .001). In 745 men having valid distal radius scan (47 MACEs), higher cortical density (Ct.BMD) and higher cortical thickness (Ct.Th^d ) were associated with lower risk of MACE. This risk was higher in men in the lowest quintile of cortical measures versus the four upper quintiles combined (Ct.BMD: HR = 2.12, 95% confidence interval [CI] 1.08-4.17, p < .025). Findings were similar in 779 men having valid distal tibia scan (48 MACEs). At both sites, higher estimated stiffness and higher failure load were associated with a lower risk of MACE. The risk of MACE was higher in men in the lowest quintile of the measures of bone strength versus four upper quintiles jointly (distal radius stiffness: HR = 2.46, 95% CI 1.27-4.74, p < .01). Similar results were obtained in 638 men without prior fragility fracture and in 689 men without ischemic heart disease at baseline. Thus, in older men followed prospectively for 8 years, higher aBMD, preserved cortical bone status, and higher estimated bone strength were associated with lower risk of MACE after adjustment for relevant confounders. © 2021 American Society for Bone and Mineral Research (ASBMR).

The association between low bone mineral density and coronary artery calcification in osteoporotic and non-osteoporotic patients in a tertiary center in Saudi Arabia

BACKGROUND

Cardiovascular disease (CVD) and osteoporosis are major health-care concerns worldwide. The evidence is contradictory on whether a relationship exists between low bone mineral density (BMD) determined by dual-energy absorptiometry (DXA scan) and coronary artery calcification (CAC) measured by computed tomography. Currently, there are no data on patients from Saudi Arabia.

OBJECTIVE

Examine the relationship between CAC and BMD in both genders and study the influence of traditional coronary artery disease (CAD) risk factors and osteoporosis.

DESIGN

Retrospective, cross-sectional, analytical.

SETTING

Single tertiary care center.

PATIENTS AND METHODS

We searched radiology databases for patients who underwent both DXA and CAC score scanning within six months of each other. The inclusion criterion was an absence of any history of CAD.

MAIN OUTCOME MEASURE

Association between osteoporosis and CAC.

SAMPLE SIZE

195 (34 osteoporosic, 161 normal BMD or osteopenic) RESULTS: Most of the study population (57.4%) were females. The mean age of all patients was 63.6 (10.1) years. Participants with CAC scores of 0 were significantly younger than those who had CAC scores >0. The presence of diabetes mellitus, hypertension, and hypercholesterolemia was higher in patients with CAC scores >0. CAC score and other CAD risk factors were not significantly different between the osteoporotic and nonosteoporotic groups, except for body mass index. A high CAC score (>100) was present in 28%, 20%, 11%, and 30% of participants with no osteoporosis, osteoporosis of the lumbar spine, osteoporosis of the femoral neck, and participants with osteoporosis of both the lumbar spine and femoral neck, respectively (P=.762), suggesting there is no association between CAC and the presence of osteoporosis.

CONCLUSIONS

Osteoporosis is not associated with higher CAC scores in Saudi Arabia and CAD risk factors are not significantly prevalent in osteoporosis. It appears that CAC and osteoporosis are independent age-related diseases that share common risk factors.

LIMITATIONS

Single-center, retrospective.

CONFLICT OF INTEREST

None.

Relationship of volumetric bone mineral density by quantitative computed tomography with abdominal aortic calcification

OBJECTIVE

This multicenter study aimed to evaluate the association between volumetric bone mineral density (vBMD) and abdominal aortic calcification (AAC) in a Chinese population.

METHODS

Quantitative computed tomography (QCT) and Agatston score (AS) were used to measure vBMD and AAC, respectively, in 3457 participants during 2013-2017. The association between vBMD and AAC was assessed using multivariate regression analysis, adjusted for age, residence, education, body mass index, and other cardiovascular risk factors.

RESULTS

The mean age of women and men was 61.4 and 62.7 years, respectively. In total, 30.4% of women and 37.7% of men were found to have AAC. After full adjustment, higher vBMD was associated with lower AAC score (β, -0.095; 95% confidence interval [CI], -0.167 to -0.024; P = 0.0087) and lower AAC prevalence (odds ratio [OR], 0.873; 95% CI, 0.824 to 0.924; P < 0.0001) in men. Inverse trends were also observed in the association of vBMD quartile with AAC severity (lowest vs highest quartile; β = 0.235; 95% CI, 0.011 to 0.459; P_trend < 0.0001) and AAC prevalence (lowest vs highest quartile; OR = 1.329; 95% CI, 1.087 to 1.625; P_trend < 0.0001) in men. However, no significant result was obtained in women, except for the association between quartiles of vBMD and AAC score.

CONCLUSIONS

In our study, vBMD was inversely associated with AAC among men independent of age and shared risk factors. However, the association was not significant among women.

Association of bone mineral density and trabecular bone score with cardiovascular disease

Traditionally, osteoporosis and cardiovascular disease (CVD) are considered as separate chronic diseases. Increasing evidence now links osteoporosis with hypertension, abnormal lipid metabolism, atherosclerosis, vascular calcification (VC), and congestive heart failure. VC coexists with bone loss, and aortic calcification is a strong predictor of low bone mineral density (BMD) and fragility fractures. The same holds true for coronary artery calcification (CAC): the lower the BMD, the higher the CAC. Trabecular bone score (TBS) iNsight software can analyze the existing BMD database to obtain the bony microstructure score (TBS). Many TBS-related studies include fracture risk, normal aging, diabetes, potential genes, obesity, and asthma severity prediction. The inverse relationship of TBS to VC may provide insight into bone–vascular interactions in chronic kidney disease. A higher TBS has been associated with moderate, but not high, CAC. One explanation is that bone microstructural remodeling becomes more active during early coronary calcification. Increased risk of 10-year likelihood of hip fracture and major osteoporotic fracture as estimated by the fracture risk assessment tool FRAX^® is significantly and independently associated with more severe CAC scores. Dual-energy X-ray absorptiometry and FRAX^® can be used to predict fracture risk and CAC scores, identifying patients who may benefit from early intervention. This review will discuss the relationship and possible mechanism of BMD, TBS, and FRAX^® with CVD and VC or CAC.

Abdominal aortic calcification and the risk of bone fractures: a meta-analysis of prospective cohort studies

The relationship between abdominal aortic calcification (AAC) and bone fracture has been examined by some observational studies, but the results remain discordant. Therefore, we aimed to assess the link between them by conducting a meta-analysis of prospective studies. Relevant studies were identified by searching PubMed and EMBASE databases until the end of December 2016. Summary relative risks (RRs) and 95% confidence intervals (CIs) for associations between AAC and fracture risk were estimated with fixed- or random- effects models. Seven prospective studies were included in the final analysis. The summarized RRs of any type of fractures for the highest compared with the lowest category of AAC were 1.64 (95% CI 1.30-2.07, P = 0.000) with mild heterogeneity (I ² = 30.1%, P = 0.188). Subgroup analysis showed that the association between AAC and fracture was not significantly modified by gender and follow-up length. Risks were similar when analyses were restricted to the studies with adjustment for bone mineral density (BMD) (RR = 1.76, 95% CI 1.31-2.38, P = 0.000, I ² = 49.1%). For the specific type of fracture, severe AAC was significantly related with hip fracture (RR = 1.64, 95% CI 1.22-2.20, P = 0.001, n = 5), but not with vertebral (RR = 1.45, 95% CI 0.81-2.58, P = 0.213, n = 3) or non-vertebral fracture (RR = 1.35, 95% CI 0.96-1.88, P = 0.081, n = 3). There was no evidence of publication bias. Our findings demonstrated that AAC was significantly and independently associated with a higher fracture risk, especially for hip fracture.

Association of ectopic fat with abdominal aorto-illiac and coronary artery calcification in african ancestry men

BACKGROUND AND AIMS

There is strong evidence that fat accumulating in non-adipose sites, "ectopic fat", is associated with cardiovascular disease (CVD), including vascular calcification. Most previous studies of this association have assessed only a single ectopic fat depot. Therefore, our aim was to assess the association of total, regional, and ectopic fat with abdominal aorto-illiac calcification (AAC) and coronary artery calcification (CAC) in 798 African ancestry men.

METHODS

Participants (mean age 62) were from the Tobago Bone Health Study cohort. Adiposity was assessed via clinical examination, dual x-ray absorptiometry, and computed tomography (CT). Ectopic fat depots included: abdominal visceral adipose tissue (VAT), liver attenuation, and calf intermuscular adipose tissue (IMAT). Vascular calcification was assessed by CT and quantified as present versus absent. Associations were tested using multiple logistic regression adjusted for traditional cardiovascular risk factors. Models of ectopic fat were additionally adjusted for total body fat and standing height.

RESULTS

All adiposity measures, except VAT, were associated with AAC. Lower liver attenuation or greater calf IMAT was associated with 1.2-1.3-fold increased odds of AAC (p < 0.03 for both), though calf IMAT was a stronger predictor than liver attenuation (p < 0.001) when entered in a single model. No ectopic fat measure was associated with CAC.

CONCLUSIONS

Greater adiposity in the skeletal muscle and liver, but not in the visceral compartment, was associated with increased odds of AAC in African ancestry men. These results highlight the potential importance of both quantity and location of adiposity accumulation throughout the body.

Abdominal lean muscle is associated with lower mortality among kidney waitlist candidates

Morphometric assessments, such as muscle density and body fat distribution, have emerged as strong predictors of cardiovascular risk and postoperative morbidity and mortality. To date, no study has examined morphometric mortality risk prediction among kidney transplant (KT) candidates. KT candidates, waitlisted 2008-2009, were identified (n=96) and followed to the earliest of transplant, death, or administrative end of study. Morphometric measures, including abdominal adipose tissue, paraspinous and psoas muscle composition, and aortic calcification, were measured from CTs. Risk of waitlist mortality was examined using Cox proportional hazard regression. On adjusted analyses, radiologic measures remained independently and significantly associated with lower waitlist mortality; the addition of radiologic measures significantly improved model predictive ability over models containing traditional risk factors alone (net reclassification index: 0.56, 95% CI: 0.31-0.75). Higher psoas muscle attenuation (indicative of leaner muscle) was associated with decreased risk of death (aHR: 0.93, 95% CI: 0.91-0.96, P<.001), and for each unit increase in lean paraspinous volume, there was an associated 2% decreased risk for death (aHR: 0.98, 95% CI: 0.96-0.99, P=.03). Radiologic measures of lean muscle mass, such as psoas muscle attenuation and paraspinous lean volume, may improve waitlist mortality risk prediction and candidate selection.

Lower leg arterial calcification assessed by high-resolution peripheral quantitative computed tomography is associated with bone microstructure abnormalities in women

In older women, the presence of lower leg arterial calcification assessed by high-resolution peripheral quantitative computed tomography is associated with relevant bone microstructure abnormalities at the distal tibia and distal radius.

INTRODUCTION

Here, we report the relationships of bone geometry, volumetric bone mineral density (BMD) and bone microarchitecture with lower leg arterial calcification (LLAC) as assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT).

METHODS

We utilized the Hertfordshire Cohort Study (HCS), where we were able to study associations between measures obtained from HR-pQCT of the distal radius and distal tibia in 341 participants with or without LLAC. Statistical analyses were performed separately for women and men. We used linear regression models to investigate the cross-sectional relationships between LLAC and bone parameters.

RESULTS

The mean (SD) age of participants was 76.4 (2.6) and 76.1 (2.5) years in women and men, respectively. One hundred and eleven of 341 participants (32.6 %) had LLAC that were visible and quantifiable by HR-pQCT. The prevalence of LLAC was higher in men than in women (46.4 % (n = 83) vs. 17.3 % (n = 28), p < 0.001). After adjustment for confounding factors, we found that women with LLAC had substantially lower Ct.area (β = -0.33, p = 0.016), lower Tb.N (β = -0.54, p = 0.013) and higher Tb.Sp (β = 0.54, p = 0.012) at the distal tibia and lower Tb.Th (β = -0.49, p = 0.027) at the distal radius compared with participants without LLAC. Distal radial or tibial bone parameter analyses in men according to their LLAC status revealed no significant differences with the exception of Tb.N (β = 0.27, p = 0.035) at the distal tibia.

CONCLUSION

In the HCS, the presence of LLAC assessed by HR-pQCT was associated with relevant bone microstructure abnormalities in women. These findings need to be replicated and further research should study possible pathophysiological links between vascular calcification and osteoporosis.

TBS Predict Coronary Artery Calcification in Adults

Purpose. This study analyzes the association between the bony microarchitecture score (trabecular bone score, TBS) and coronary artery calcification (CAC) in adults undergoing health exams. Materials and Methods. We retrospectively collected subjects (N = 81) who underwent coronary computed tomography and bone mineral density studies simultaneously. CAC was categorized to three levels (Group 0, G0, no CAC, score = 0, N = 45; Group 1, G1, moderate CAC, score = 1–100, N = 17; Group 2, G2, high CAC, score ≧ 101, N = 19). Multinomial logistic regression was used to study the association between TBS and CAC levels. Results. CAC is present in 44.4% of the population. Mean TBS ± SD was 1.399 ± 0.090. Per 1 SD increase in TBS, the unadjusted odds ratio (2.393) of moderate CAC compared with no CAC was significantly increased (95% CI, 1.219–4.696, p = 0.011). However, there has been no association of TBS with high CAC (OR: 1.026, 95% CI: 0.586–1.797, p = 0.928). These relationships also existed when individually adjusted for age, sex, and multiple other covariates. Conclusions. Higher TBS was related to moderate CAC, but not high CAC; a possible explanation may be that bone microarchitecture remodeling becomes more active when early coronary artery calcification occurs. However, further researches are needed to clarify this pathophysiology.

Abdominal aortic calcification: A reappraisal of epidemiological and pathophysiological data

In men and women, there is a significant association between the risk of cardiovascular event (myocardial infarction, stroke) and risk of major fragility fracture (hip, vertebra). Abdominal aortic calcification (AAC) can be assessed using semiquantitative scores on spine radiographs and spine scans obtained by DXA. Severe AAC is associated with higher risk of major cardiovascular event. Not only does severe AAC reflect poor cardiovascular health status, but also directly disturbs blood flow in the vascular system. Severe (but not mild or moderate) AAC is associated with lower bone mineral density (BMD), faster bone loss and higher risk of major fragility fracture. The fracture risk remains increased after adjustment for BMD and other potential risk factors. The association between severe AAC and fracture risk was found in both sexes, mainly in the follow-ups of less than 10years. Many factors contribute to initiation and progression of AAC: lifestyle, co-morbidities, inorganic ions, dyslipidemia, hormones, cytokines (e.g. inflammatory cytokines, RANKL), matrix vesicles, microRNAs, structural proteins (e.g. elastin), vitamin K-dependent proteins, and medications (e.g. vitamin K antagonists). Osteogenic transdifferentiation of vascular smooth muscle cells (VSMC) and circulating osteoprogenitors penetrating into vascular wall plays a major role in the AAC initiation and progression. Vitamin K-dependent proteins protect vascular tunica media against formation of calcified deposits (matrix GLA protein, GLA-rich protein) and against VSMC apoptosis (Gas6). Further studies are needed to investigate clinical utility of AAC for the assessment of fracture and cardiovascular risk at the individual level and develop new medications permitting to prevent AAC progression.

Decreased bone cortical density at the forearm in subjects with subclinical peripheral arterial disease

The association between peripheral arterial disease (PAD) and low bone mass is controversial. In our study, peripheral quantitative computed tomography shows a reduction of cortical but not trabecular, bone mineral density (BMD) at the forearm, in patients with subclinical PAD.

INTRODUCTION

Some controversy exists regarding the association between peripheral arterial disease (PAD) and low bone mass. Previous studies have evaluated bone mineral density (BMD) in patients with subclinical PAD, with mixed results. Inconsistency of data may depend on the fact that most studies measured areal bone mineral density (aBMD) by Dual-energy-x ray absorptiometry (DXA). Because DXA cannot distinguish between cortical and trabecular compartments, we reasoned that a study aimed to establish whether these compartments were differentially affected by PAD status could give more information on the nature of this association.

METHODS

In this cross-sectional study, we used peripheral quantitative computed tomography (pQCT) to examine volumetric cortical and trabecular mineral density at the radius (vBMD) in a cohort of subjects with subclinical PAD as defined by ABI ≤0.90 and compared them with healthy subjects with no evidence of PAD.

RESULTS

Patients with subclinical PAD had significantly reduced cortical density (1101.0 ± 45.4 vs 1156.2 ± 51.3 mg/cm(3), p < 0.001) and cortical area (75.0 ± 20.9 vs 99.9 ± 18.2 mm(2), p < 0.001) than healthy subjects. Trabecular density (178.1 ± 47.9 vs 165.8 ± 29.6 mg/cm(3)) was not significantly different in the two groups.

CONCLUSION

Subclinical PAD induces a selective bone loss at the radius compartment, not identified by standard DXA, which seems to occur primarily at the cortical level.

Interactions between dietary calcium intake and bone mineral density or bone geometry in a low calcium intake population (KNHANES IV 2008-2010)

CONTEXT

Little is known about the interactions between dietary calcium intake and bone strength parameters in populations or areas with low calcium intake.

OBJECTIVE

The objective of the study was to investigate the relationship between dietary calcium intake and bone mineral density (BMD) or bone geometry in an Asian population with low calcium intake.

DESIGN AND SETTING

This was a cross-sectional study of data from the Korea National Health and Nutrition Examination Survey, 2008-2010.

PARTICIPANTS

A total of 3448 men and 3812 women older than 50 years were stratified by daily dietary calcium intake: less than 400 mg/d, 400-799 mg/d, 800-1199 mg/d, and 1200 mg/d or greater.

MAIN OUTCOME MEASURES

BMD was measured by dual-energy X-ray absorptiometry and the geometric index was calculated.

RESULTS

Mean daily calcium intake was 470 mg/d in this population. BMD in the lumbar spine (both sexes) and femoral neck (women) was significantly lower only when calcium intake was less than 400 mg/d. In men, femoral neck and total hip BMD was positively related to calcium intake up to 1200 mg/d. Calcium intake less than 400 mg/d was negatively related to femoral cortical thickness and buckling ratio. These interactions disappeared when the 25-hydroxyvitamin D level was 30 ng/mL or greater in men and 20 ng/mL or greater in women.

CONCLUSIONS

Low calcium intake was significantly related with low BMD and increased risk of osteoporosis. However, the association between calcium and BMD was not consistently linear, and a sufficient vitamin D level appears to compensate for the negative influences of low calcium intake on bone.